A long-time senior adviser to Ronald Reagan quit his job yesterday amid signs of dissension in Reagan's presidential campaign staff.

Lyn Nofziger, who has worked as a top aide to Reagan in every campaign since he first ran for governor of California in 1966, submitted his resignation to the undeclared 1980 presidential hopeful yesterday.

Jim Lake, press secretary of the Reagan for President campaign, confirmed that Reagan had accepted the resignation but would offer no explanation of the apparently sudden blowup.

Nofziger could not be reached immediately for comment.

But friends of Nofziger and associates on this and past campaigns all said they believed the resignation was the result of disagreements between Nofziger and John P. Sears, Reagan's campaign manager, and Michael J. Deaver, Reagan's public relations adviser.

The disagreements were said to involve both personality clashes and a dispute about how far Reagan should go in 1980 to moderate his conservative image.

Nofziger reportedly had been arguing against the Sears-Deaver push to make the GOP front-runner more of a middle-road candidate for 1980.

The unexpected resgination was seen by leaders of rival Republican camps as confirming Sears' primacy in the Regan circle, but also as indicating tensions that may cause future problems for the Reagan organization.

These sources said the rift between Sears and Nofziger began developing in 1976, when Sears arranged for Nofziger to be taken out of the top command and sent to California to run the successful Reagan effort against President Ford in that primary.

After Reagan's defeat at the 1976 nominating convention, Nofziger set up and ran a group called Citizens for the Republic, a conservative political action committee that was used to keep Regan's national organization intact.

Late last year, according to these sources, Nofziger proposed a campaign structure for 1980 that would have given direction of the organization to him and Deaver and left Sears basically running the Reagan effort in the Northeast.

Sears reportedly told Reagan he would not work for him on those terms, and the plan was scrapped.

Instead, Nofziger was put in charge of Reagan's fund raising -- a new area for him -- and given responsibility for the important Texas primary.

It could not be learned what had provoked Nofziger's resignation, but the decision, apparently reached over the weekend, was a sudden one. Anderson Carter, another Reagan aide and long-time friend of Nofziger, said he had conferred with Nofziger Friday in Reagan's Los Angeles headquarters about the Texas situation and said Nofziger had indicated no intention of quitting.

Lake said only that Nofziger had written a letter of resignation to Reagan and had discussed it with the former governor yesterday.

"The governor felt Lyn knew his own circumstances best and agreed to accept the resignation," Lake said. "They parted as friends and the governor told me that Lyn will remain a supporter and a confidant."

Reagan is expected to announce his candidacy formally later this fall and is leading in the polls for the 1980 nomination.

Nofziger, who came to Washington in the 1950s for the Copley Newspapers and stayed to work for a time for both the Nixon White House and the Republican National Committee, was regarded as one of Reagan's most loyal followers.

He was a major adviser in Reagan's two successful campaigns for governor and in his losing bids for the presidential nomination in 1968 and 1976.