Seagram Co. said Friday it bought an additional 1.4% of Time Warner Inc., bringing its total stake to 13.1% or $ 1.9 billion. Sources had reported Seagram’s return to the market three weeks ago (Daily Variety, Feb. 9) after a brief hiatus following Time Warner’s Jan. 20 adoption of an anti-takeover plan.Time Warner had no comment on the purchase. Its poison pill, meant to ward off a creeping takeover — the acquisition of control at a discount — kicks in if any outside party attempts to buy more than 15%. Seagram has said previously it did not intend its stake to exceed 15% of the media titan’s 375 million shares outstanding. Time Warner shares closed at 37 7/8, up 1/4.