Henley Group Inc. bought 7.9 million shares,...

Henley Group Inc. bought 7.9 million shares, equal to a 5.03% interest, in Santa Fe Southern Pacific Corp. stock last year, the La Jolla-based company said in a 10-K statement filed Friday with the Securities and Exchange Commission.

Henley and Santa Fe both issued statements saying the Henley shares were bought for investment purposes.

But speculation that Henley might boost its holdings helped push Santa Fe stock up 1 7/8 to 38 in New York Stock Exchange trading Monday. Henley closed off five-eighths at 26 1/8 in over-the-counter trading.

Henley paid $261 million for the shares in several transactions in 1986 and has acquired no additional shares this year, a Henley spokesman said. As of Dec. 31, the shares constituted a 4.93% interest in Sante Fe. But Santa Fe’s stock repurchase program this year has reduced its total shares outstanding and raised Henley’s percentage owned.

Because Henley did not “actively� acquire its 5% stake in Santa Fe shares, it was not required to file a 13-D report with the SEC upon making the stock acquisition last year, the Henley spokesman said.

Burton Strauss, an analyst with New York-based E.F. Hutton who follows Santa Fe, said Henley may be betting that the Interstate Commerce Commission will reconsider its rejection of the proposed merger of Santa Fe and Southern Pacific rail lines last year. Santa Fe has asked the ICC to reconsider. An ICC approval of the rail merger would probably benefit the Santa Fe stock price, Strauss said.