Jtb106 has got it right, R/R had a bad time developing the RB211, it was more advanced than the JT9, and to a lesser extent, the CF-6. R/R staked a lot on a material for the fan-blades called Hyfill, very light but supposdly very strong too. In tests it was found that Hyfill couldn't stand up well to hail, let alone bird-strikes.
Development costs shot-up, and R/R went bankrupt. Lockheed suddenly found they were building gliders. R/R, being a vital defence contractor, were bailed out by a Conservative British goverment, (the irony!), and fixed the RB211, which went on to be, IMHO the best of the engines.
But the time lost allowed the definitive DC10-30, with more powerful CF6-50 engines, to take the medium/long-haul market.
Eventually more powerful RB211's became available for the L1011, and 747 too.
The short/medium haul market for the early L1011's, (and DC10-10's too), was destroyed by the advent of the Airbus A300.
Sad story, the L1011 was a fine airplane from an always innovative company. It was launched before the DC-10, but the DC-10 flew first. Later it was clear that a few corners had been cut in it's development.
Adding to the L1011's woes, was the recession of the early 1970's, all three US wide-body makers were in trouble, and were helped by the Nixon admistration. But Lockheed never really recovered, and were probably glad to get out of the market in the early 1980's.