Thomas C. Pulliam Jr., the former Prince George's County bank officer convicted of bank fraud in September, was sentenced today to two years in federal prison.

Pulliam, 38, stood somberly as U.S. District Judge Joseph C. Howard said that he was heavily influenced in his sentencing by Pulliam's reluctance to accept responsiblity for his crime.

Although Pulliam pleaded guilty and told Howard before sentencing that "I am very sorry," the judge said, "I seem to be getting the impression you are manipulating others in order to extricate yourself."

Pulliam, former executive vice president of Jefferson Bank and Trust Co., a politically connected bank in Capitol Heights, had no comment on his sentence. Both prosecution and defense attorneys said he can expect to serve a minimum of 14 months in prison under federal parole guidelines. He could have received a maximun sentence of five years in prison and a $10,000 fine. He was given permission to remain free until Jan. 4.

The investigation of Pulliam began in September 1981 when bank officials discovered a loan that led to his conviction and fired him. Questions about Pulliam's conduct at Jefferson also prompted a broader probe of the bank's overall lending policies. Last April, the state took the unusual step of accusing the bank of operating in an "unsafe and unsound" manner after federal bank examiners found that nearly 40 percent of the bank's $8 million in loans were unacceptably risky. The bank then signed an agreement with the state in which it pledged to correct any problems.

Jefferson, which opened more than two years ago, has among its stockholders several prominent Prince George's businessmen and politicians, including County Executive Lawrence J. Hogan, county Planning Board Chairman Charles A. Dukes Jr., county liquor board member Gerard F. Holcomb and developer Kenneth H. Michael

The bank's board chairman, Raymond G. LaPlaca, a politically active county businessman, and his predecessor, Dukes, who is the bank's counsel, have said that Jefferson has corrected its problems and is complying with federal and state banking regulations. LaPlaca and Dukes have said that Pulliam was chiefly responsible for Jefferson's difficulties.

In the months before Pulliam's trial, the government tried to strike a deal with him in return for his help in determining whether other bank officials or directors had misused the institution. Pulliam refused to plea bargain and went to trial instead.

The trial ended abruptly when, in the face of new government evidence, Pulliam pleaded guilty to conspiring to obtaining a $25,000 Jefferson loan by making it in the name of a fictitious person.

The FBI investigation of Jefferson is still pending. Assistant U.S. Attorney James P. Ulwick asked in court today that Pulliam receive nearly the maximun sentence, four years in prison, an indication that Pulliam has not agreed to cooperate in any government investigation.

Stanley J. Reed, Pulliam's attorney, said in court that Pulliam recently has been working with Jefferson officials to try to help the bank recover some past bad loans. Reed said a civil suit Jefferson filed against Pulliam to recover the $25,000 loan that led to his conviction is "in a state of suspended animation."

In an interview later, Reed said Pulliam's work on Jefferson's behalf is "very informal" and the bank is not paying him for his services.

Riley B. Carter II, a Jefferson director and longtime Pulliam friend, attended the sentencing and chatted with Pulliam.

Pulliam's four character witnesses included two men who received loans from him at Jefferson. Michael J. Morfessis, an operator of a restaurant equipment and design company, and Eston (Mickey) Lewis, a Washington bail bondsman and restaurant owner, both testified that Pulliam was a considerate loan officer who granted them loans when other banks refused to help them.

At his trial, prosecutors contended that Pulliam used $10,000 from the $25,000 loan made in a fake name and $12,000 from another loan to help finance his half interest in a satellite television antenna business he was starting.

Pulliam changed his plea to guilty after a surprise witness gave prosecutors evidence that Pulliam had admitted in sworn testimony during a 1976 child custody suit that he made two other loans in fake names while employed at another bank in the mid-1970s.

Pulliam, who initially denied on the witness stand that he made the Jefferson loan to a nonexistent person, admitted when he pleaded guilty that he knew the loan was made in a fictious name.

Judge Howard said today that in subsequent interviews with probation officials Pulliam indicated he was having second thoughts about his plea and criticized the prosecutor and his attorney.