The Baltimore Orioles picked up an $850,000 option on relief pitcher Tom Niedenfuer, guaranteeing he'll be with them in 1988.

"Tom will be back next year," said Larry Lucchino, club vice president. Monday was the deadline for picking up a player's option year or losing him to free agency.

Lucchino said the Orioles are discussing with Niedenfuer's agent, Tom Reich, contract terms other than just 1988. Acquired in May, Niedenfuer saved 13 games for Baltimore this year.

Lucchino said he was "still negotiating" with shortstop Cal Ripken Jr., who is eligible for free agency, but said the two sides were not close. Lucchino said he had a series of meetings set up this week with Ron Shapiro, who represents Ripken . . .

Players have until Nov. 9 to file for free agency. Approximately 110 are eligible and 15 have declared, the latest Brett Butler and Ed Vande Berg of the Indians and Lee Mazzilli, Mets . . .

The Minnesota Twins will receive winning World Series shares of $85,580, the losing St. Louis Cardinals $56,052, according to published reports.

Both figures are below last year, when the champion New York Mets earned a record $86,254 per full share, the Boston Red Sox $74,985. Reportedly, the Twins voted 40 3/4 shares and the Cardinals voted 35 3/4 shares.