KT said on Jan. 4 that its in-house large-scale AI model, Mideum K, ranked No. 1 among South Korea’s mid-sized models on the AAII (Artificial Analysis Intelligence Index), a platform that comprehensively evaluates the performance of global AI models.

In the evaluation, Mideum K recorded strong scores overall across more than 10 core categories including reasoning, expert knowledge, math and programming, and agent execution capabilities.

In the AAII results, Mideum K scored 87 percent on tau^2-bench, one of the major agent performance benchmarks, placing it among the top models in agentic AI.

Tau^2-bench is an agent-focused benchmark that evaluates whether AI can collaborate with humans in real work environments and use multiple tools to complete tasks end to end. KT said Mideum K’s score is at a top level and matched Google’s latest model, Gemini 3.

KT said Mideum K also posted strong and balanced results on key benchmarks such as MMLU Pro, GPQA and HLE, which assess expert knowledge and advanced reasoning ability. It achieved a top domestic level on indicators of Korean language understanding.

A KT official said the results are more notable because they were achieved with a model in the under-40B-parameter class.

KT said it secured top-level performance both in instruction following, which accurately understands complex user instructions, and in Korea-specific performance, which fully understands Korea’s unique linguistic and social context, while improving efficiency by reducing the burden of large-scale GPU infrastructure.

KT built Mideum K using a from-scratch approach, carrying out the entire process in-house from model architecture design to training data construction. It said this produced the “most Korean” AI optimized for the Korean corporate environment.

KT targeted the B2B market from the early stages of development. Its strategy is to provide customized AI agents that automate and independently handle real corporate tasks by industry, including finance, public services and manufacturing, while leading enterprise customers’ AX.

Oh Seung-pil, head of KT’s Technology Innovation division and a vice president, said the AAII listing objectively demonstrates that KT’s in-house AI technology has reached global standards. He said the company will become the best AI partner to drive work innovation and digital transformation for Korean companies through agentic AI.