KERSEY IN THE MONEY: Jerome Kersey, who escaped serious injury earlier in the week, yesterday finalized an $11 million, four-year extension of his contract with the Portland Trail Blazers.

The Trail Blazers declined to release terms of the deal. But Kersey said after the agreement that he would earn about $11 million through the 1995-96 season.

Kersey had agreed to the extension on Tuesday, hours before the Trail Blazers' game against the Los Angeles Lakers. But he had not signed the contract.

In the first quarter of that game, Kersey was undercut by a teammate and landed hard on his head. Although he did not return, the injury was not considered serious.

The 6-foot-7 Kersey had played in 123 consecutive games going into last night's home game against Detroit, the first meeting of the clubs since The NBA finals last June.

Kersey, in his seventh year, averaged 16 points per game last season as the Trail Blazers went 59-23.

Kersey's contract extension is the last of three major deals between the Trail Blazers and returning starters from the 1989-90 Western Conference champion team. Portland earlier reached agreements with Clyde Drexler and Buck Williams.